Chopper for glass strands



April 28, 1970 R. M. STREAM CHOPPER FOR GLASS STRANDS Filed 001:. 4, 1967 3 Sheets-Sheet 1 INVENTOR.

Arromvms April 28, 1970 R. M. STREAM CHOPPER FOR GLASS STRANDS 3 Sheets-Sheet 2 Filed Oct. 4. 1967 IN VENTOR. PAL PH M STREAM ATTORNEYS April 28, 1970 R; M. STREAM 3,508,461

CHSPPER FOR GLASS STRANDS Filed 001;. 4, 1967 3 Sheets-Sheet INVENTOR.

A 44 PH M 577954 ATTORNEYS United States Patent 3,508,461 CHOPPER FOR GLASS STRANDS Ralph M. Stream, Newark, Ohio, assignor to Owens- Corning Fiberglas Corporation, a corporation of Delaware Filed Oct. 4, 1967, Ser. No. 672,908

Int. Cl. B23d 25/12 U.S. Cl. 83-344 Claims ABSTRACT OF THE DISCLOSURE A chopper for cutting continuous glass strands into short lengths having a cutter roll and a cot roll of greater diameter between which the strands are directed, the straight blades of the cutter roll projecting generally radially therefrom but angled slightly to the long axis of the cutter roll as they extend lengthwise thereon and arranged to form matching notches in the surface of the cot roll which are repeatedly entered and engaged by the blades to cut the strands and provide a driving relation between the cutter roll and the cot roll, there being a spring forcing the rolls toward each other and an adjustable stop limiting the penetration of the notches by the blades.

This invention relates broadly to the drawing of continuous filaments from a source of molten glass, gathering the filaments into strands and cutting the strands into short lengths principally for use as a reinforcing medium in plastic molding. More particularly the invention pertains to an improved chopper for cutting the strands.

The prior art is believed to be well exemplified by the disclosure of U.S. Patent No. 2,719,336 which issued to Richard V. Stotler on Oct. 4, 1955. As shown therein, the chopper receives strands from packages or as gathered continuous filaments from a filament forming source. The chopper includes a cutter roll with radially extending blades, a cot roll and an idler roll riding upon the driven cot roll.

While such a chopper has had long commercial success frequent replacement or repair of the cot roll has been a heavy maintenance expense and the production rate has been lower than desired.

The principal object of this invention is the provision of an improved chopper which operates smoothly at higher speeds, has accordingly greater production capacity, and processes strands directly as gathered from a continuous filament forming source.

A further important object of the invention is a chopper which is subject to less wear and maintenance cost and has lower power requirements.

These and other objects and advantages of the invention are attained at least in part by having angled blades on the cutter roll, by having the diameters of the cutter roll and cot roll so proportioned that the blades continue to enter the notches first cut into the cot roll by the blades, and having a cot roll of a diameter considerably larger than that of the cutter roll.

A more complete explanation of the invention is presented hereafter in connection with the accompanying drawings in which:

FIGURE 1 is a side elevation of a chopper embodying one form of the invention and apparatus associated therewith shown rather diagrammatically for drawing continuous glass filaments from a molten glass source and gathering the filaments into a plurality of strands for delivery to the chopper;

FIGURE 2 is an end elevation of the chopper as viewed from the line 2-2 of FIGURE 1;

FIGURE 3 is a longitudinal, vertical section of a chopper embodying an alternate form of the invention;

FIGURE 4 is an elevational view of the right hand end of the chopper of FIGURE 3;

FIGURE 5 is an enlarged vertical section of the contact area of the cutter roll and cot roll of the chopper of FIGURES 3 and 4;

FIGURE 6 is a plan view of the chopper of FIGURES 3 and 4; and

FIGURE 7 is an enlarged view with portions in section of the cutter roll of the chopper of FIGURES 3, 4 and 6 and five strands, diagrammatically indicated, being cut into short lengths by the cutter roll.

Referring to the drawings in more detail the strand chopper 10 shown in FIGURES 1 and 2 has a cot roll 12 which also serves as a filament pull wheel. The cutter roll 13 has radially extending blades 14 which engage the peripheral surface of the cot roll 12. The cot roll is driven through belt 15 and pulley 16 by a motor which is not illustrated. The cutter roll is driven by the cot roll through the engagement between the blades 14 and the notches formed by the blades in the peripheral surface of the cot roll. The blades 14 repeatedly severe the strands 19 passing between the two rolls into short lengths 17, most commonly either one quarter or one half inch in length, which are collected on the conveyor 18.

The strands 19 are gatherings of continuous filaments 20 drawn downwardly from minute streams of molten glass issuing from the tips 21 of the bushing 23 to which the molten glass is delivered from a glass furnace. Conventionally there are between two and four hundred tips in such a bushing.

The filaments are initially divided by the insertion of fingers 25 into strands groups each of which may usually include from twenty to eighty or more filaments. Thus segregated the filaments pass over the apron of the size applicator 27. The strand groups of filaments are consolidated into compact strands by riding around grooves in the shoe 28. The strands then pass around the idler wheel 29 in spaced relation before traveling upwardly upon the peripheral surface of the cot roll. The frictional adhesion of the strands to the extended peripheral surface of the extra large cot roll is sufficient to generate the pulling force required to draw the filaments 20 from the bushing 23.

The size applicator, grooved shoe and idler wheel are of conventional design comparable to those shown and more fully described in U.S. Patent No. 3,265,482 which issued Aug. 9, 1966, to Langlois and Stream.

The overhanging or outboard positioning of the cot roll 12 in respect to the casing 30 of the strand cutter and on the end of the shaft 32 as seen in FIGURE 2 facilitates lacing of the strands around the cot roll at the start of operations. The cot roll has a diameter, in this instance of approximately thirteen inches to provide the circumferential surface required in its function as a pull wheel.

The cot roll 12 has a width close to four inches and has a peripheral surface of a polyurethane composition tough and resilient in nature.

The cutter roll 13 is only about four inches in diameter inclusive of the blades which project outwardly three eighths of an inch. A cutter roll of this diameter has been found to function satisfactorily and may be built more accurately and at less expense than a larger model.

The cot roll shaft 32 is upported upon bearings mounted on the edges of casing 30. The shaft 33 of the cutter roll 13 is held within bearings fixed to the upper ends of a pair of rocker arms one of which is indicated at 34 in FIGURE 1. The lower ends of the rocker arms are pivotally carried on shaft 35. Fixed to the center of the shaft 35 between the rocker arms is a collar 37. A horizontal arm 38 projects from this collar to extend exteriorly of the end of the casing 30.

3 A set screw 39 threaded through bracket 40 and held in selected position by lock nut 41 limits theupward movement of the projecting end of the arm 38 and therethrough limits the rotation of shaft 35 in the direction pivoting cutter roll 13 toward the cot roll 12.

A second arm 42 extends upwardly from the collar 37. fixed to shaft 35 and receives the pressure of spring 43 carried on the rod 45. The latter is threaded at its outer end for receipt of the lock nut 46. The tension of the spring swings the rocker arms on shaft 35 toward the cot roll and determines the pressure of the abutment of the blades of ,the cutter'roll against the surface of the cot roll up to the limit of movement permited by arm 38 meeting the set screw 39.

The strand chopper 48 of alternate design shown in FIGURES 3, 4 and 6 the structure is illustrated and described in more detail, and as many of the elements are similar to those of the chopper of FIGURES l and 2 the description of the alternate design will improve the understanding of the structure of the chopper 10 of FIG- URES land 2.

In this modification the cutter roll 52 with its radial blades 53 instead of being supported upon rocker 'arms has end shafts 55 and 56 which are mounted in bearings 57 and 58 set upon the opposite side edges of the casing 50.

The cot roll 60 is of smaller diameter (about six inches) than the cot roll 12 of the easlier described model and is lodged with its lower portion Within the casing 50. Access to it is not so essential nor is the large size, as here it does not serve as a pull Wheel but instead is adapted to receive strands from packages mounted upon a creel.

The cot roll 60 includes an inner cylidnrical shell 61 encompassed by a resilient sleeve 62 about five eighths of an inch thick of a polyurethane composition. The sleeve is held in place by end retainers 63 and 64. The shaft 65 of the cot roll extends through end hubs to rest in bearings 66 and 67. These are mounted upon the upper ends of rocker arms 68 and 69 similar to those supporting the cutter roll 13 of the chopper 10 of FIGURES 1 and 2. The rocker arms are carried upon the pivot shaft 71 turnable in bearings 72 and 73.

A collar 75 is fixed to the center of shaft 71. Extending from the collar is the horizontal stop arm 76, the outer end of which projects exteriorly of the casing 50 through opening 77. Upward movement of the arm 76 and associated pivoting of the cot roll 60 toward the cutter roll 52 is limited by the set screw 78 threaded through bracket 79 and held in selected setting by the lock nut 80.

The upright arm 82 extending from collar 75 receives the' thrust of spring 83 held against the arm by the ad- 4. rigidly in precise position by end plates 110 and 111 fastened 'by' screws'112 and by the intervening polyurethane gaskets 113 and 114.

While the polyurethane composition of the cot roll sleeve 62 is tough and resilient, it is pierced by the blades 53, and notches 102 are quickly formedin the surface of the sleeve as illustrated in FIGURE 5. The circumferential dimension of the sleeve is selected to be evenly divided by the distance between the tips of adjacent blades and the blades are spaced evenly apart so the blades keep projecting into the notches first created by the blades. This establishes a strong traction between the cutter roll and the cot roll which synchronizes their rotation and transmits driving torque from the roll activated from a short lengths 107 as they pass between the cutterroll 52 and the cot roll 60. The line of severance 109 is parallel with and slightly above the line of tangent contact be tween the two r'olls. v p

The work load is distributed since the strands are cut successively as each angled blade, progressive from left to right as viewed in FIGURE 7, moves across the line of severance. To reduce wear of the blades the group of strands 106 are conventionally reciprocated lengthwise of the cutter roll.

The tension of spring 83 may be set by adjustment of screw'84 to apply the pressure necessary for penetration of the blades into the surface of the cot sleeve. A pressure of only 150 pounds has been found effective.

: Entry of the blades into the notches is advisably limited initially. to one thirty second of an inch.1his is controlled by positioning set screw 78 against horizontal arm 76.

*To maintain the cutting effectiveness of the blades as the notches become widened through gouging by the blades, deeper penetration is provided by outwardly turni ing of the set screw-78. Ordinarily entry of no more than justable screw 84. The latter is threaded through the end strands delivered between these rolls are pulled from the supply source,such as packages on a creel.

- Details of the cutter roll 52 are best disclosed in FIG- URES 6 and 7..In this chopper design the cutter roll is driven through pulley 99 on end shaft 56 with belt 100 engaging the pulley.

While the blades 53 of the cutter roll 52, as well as U those of cutter roll 13, are individually straight they are set in grooves running longitudinally of the peripheral surface of the roll but are angled slightly circumferensirable.

one-eighth of an inch is recommended. After this depth is reached the sleeve may be removed-and its surface refinished by machining in a lathe. To reestablish tracking of the blades in the notches subsequently formed the reduction in diameter must be such that'the new circumference is still exactly divisable by thedistance between adjacent blades.

With the angled blades at least two blades are engaging notches at the same time. Simultaneous engagement of additionalblades further adds to the traction and occurs when the blades are narrowly spaced for cutting the strand into short lengths such as one-eighth and one-quarter inches. Such contact of additional blades is promoted by utilizing a cot roll of larger diameter than that found most feasible for the cutter roll. The peripheral surface of the cot roll does not then reced'e so rapidly from the contact area. A diameter for the cot, roll at leastfifty 'percent greater than that of the cutter roll is accordingly de- In summary, the features of the invention it-is desired toemphasize include the tracking. of the cutter blades in the initially formed notches, the angled positioning of the blades, the simultaneously engagement :of two or more blades in notches of the cot'roll, the cot roll having a substantiallylarger diameter than-that of the cutter roll,-one

roll driven by the other roll through the traction of the blades in the notches, the resilient pressure means abutting the rolls, the stop means limiting the abutment, the outboard mounting and thefree peripheral surface of=the cot tially of the roll.- The leading end of each blade is preferroll, and the rocker arm pivotal mounting of one of the rolls. a I

For the purpose of setting forth this invention specific apparatus has necessarily been disclosed. VaIiousmodifications and substitution of elements thereof are entirely feasible while retaining the basic features and benefits of the invention. Among the more obvious alternate arrangements are pneumatic or hydraulic devices for the spring utilized for applying pressure upon the rocker arms, and curved instead of straight blades on the cutter roll. It should also be recognized that the term strands is utilized generically herein and should be interpreted as encompassing rovings, yarn, filaments, and tapes.

I claim:

1. A chopper for cutting continuous strands of glass fibers into short lengths including a cutter roll, a cot roll having a surface of resilient material, means for delivering strands to be cut between the rolls, blades extending generally radially from the cutter in circumferentially spaced relation, longitudinally extending notches in the resilient material in spaced relation circumferentially around the cot roll, means for synchronizingly rotating the rolls, the rolls being so positioned, the diameters of the rolls being so proportioned and the spacing of the blades and notches being so matched that the blades continue unvarying to enter the notches in the resilient material, the blades contacting the surface of the notches during their presence in the notches, the strands delivered between the rolls being cut into discontinuous lengths.

2. A chopper according to claim 1 in which there is power means rotating one of the rolls and the other roll is rotated through the traction between the blades and the notches in the resilient material.

3. A chopper according to claim 2 in which the blades are slightly angled to the axis of the cutter roll as the blades extend across the circumferential surface of the cutter roll.

4. A chopper according to claim 2 in which the circumferential spacing of the blades is sufiiciently close and the penetration of the blades into the notches is sufliciently deep that at least two of the blades are constantly penetratin g notches.

5. A chopper for cutting continuous glass strands into discontinuous lengths including a rotatably mounted cutter roll, a rotatably mounted cot roll, the longitudinal surface of the cot roll being of a resilient material, means for delivering strands to be cut between the rolls, blades extending generally radially from the cutter in circumferentially spaced relation, longitudinally extending notches in spaced relation circumferentially around the cot roll in the resilient material, means for driving one of the rolls in rotation, the rolls being 50 positioned, the, diameters of the rolls being so proportioned and the spacing of the blades and notches being so matched that the blades continue unvarying to enter the notches in the resilient material the rotational energy of the driven roll being transferred to the other roll through the engagement of the blades with the cot roll in the notches, the continuous strands delivered between the rolls being cut into discontinuous lengths.

6. A chopper according to claim 5 in which the blades are slightly angled to the axis of the cutter roll as the blades extend across the circumferential surface of the cutter roll and the circumferential spacing of the blades is sufficiently close and the penetration of the blades into the notches is sufficiently deep that at least two of the blades are constantly in engagement with the material defining the notches.

7. A chopper according to claim 6 in which the blades are straight and the trailing end of each blade is at least even with the leading end of the following adjacent blade.

8. A chopper for cutting continuous strands into short lengths including a cutter roll, a cot roll, means for delivering strands to be cut between the rolls, blades extending generally radially from the cutter in circumferentially spaced relation, longitudinally extending notches in spaced relation circumferentially around the cot roll, means for synchronizingly rotating the rolls, the rolls being so positioned, the diameters of the rolls being so proportioned and the spacing of the blades and notches being so matched that the blades continue unvarying to enter the notches and thereby effect cutting of the strands delivered between the rolls, means exerting resilent pressure forcing the rolls toward each other to effect penetration of the surface material by the blades, stop means limiting the penetration. 9. A chopper fo cutting continuous strands into short lengths including a cutter roll, a cot roll, rocker means upon which one of the rolls is mounted, a pivotable shaft from which the rocker means extends, means for delivering strands to be out between the rolls, blades extending generally radially from the cutter in circumferentially spaced relation, longitudinally extending notches in spaced relation circumferentially around the cot roll, means for synchronizingly rotating the rolls, the rolls being so positioned, the diameters of the rolls being so proportioned and the spacing of the blades and notches being so matched that the blades continue unvarying to enter the notches and thereby effect cutting of the strands delivered between the rolls, means exerting resilient pressure forcing the rolls toward ach other to effect penetration of the surface material by the blades, adjustable stop means limiting the penetration, pivoting movement of the shaft being subject to the means exerting pressure against the adjustable stop means.

10. Apparatus for producing discontinuous lengths of glass strands comprising:

means for delivering a plurality of molten glass streams; means for continuously attenuating the streams into glass filaments and forming discontinuous lengths thereof comprising a cot roll having a peripheral surface of resilient material, a cutter roll, blades extending from the cutter roll in circumferentially spaced relation, notches in the resilient material circumferentially about the cot roll, means for combining the filaments into at least one glass strand, means for rotating the rolls, the rolls being so positioned, the diameters of the rolls being so proportioned and the spacing of the blades and notches being so matched that the blades enter the notches during rotation, the blades contacting the surface of the notches during their presence in the notches, the rolls advancing the glass strand between them and severing them into discontinuous lengths.

References Cited UNITED STATES PATENTS 2,248,291 7/1941 Walborn 83348 X 2,719,336 10/1955 Stotler 83347 X 2,745,491 5/1956 Sonne'born et al. 83347 X 2,808,884 10/1957 Shaun et al 83-346 X 3,130,619 4/1964 Faro 83913 X 3,176,555 4/1965 Bowker et al. 83-659 X JAMES M. MEISTER, Primary Examiner 'U.S. Cl. X.R. 83345, 347, 913 

